221025660 has 48 divisors (see below), whose sum is σ = 638840832. Its totient is φ = 57038400.

The previous prime is 221025659. The next prime is 221025709. The reversal of 221025660 is 66520122.

221025660 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a self number, because there is not a number n which added to its sum of digits gives 221025660.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 57556 + ... + 61275.

It is an arithmetic number, because the mean of its divisors is an integer number (13309184).

Almost surely, 2^221025660 is an apocalyptic number.

221025660 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

221025660 is an abundant number, since it is smaller than the sum of its proper divisors (417815172).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

221025660 is a wasteful number, since it uses less digits than its factorization.

221025660 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 118874 (or 118872 counting only the distinct ones).

The product of its (nonzero) digits is 1440, while the sum is 24.

The square root of 221025660 is about 14866.9317614631. The cubic root of 221025660 is about 604.6177582300.

Adding to 221025660 its reverse (66520122), we get a palindrome (287545782).

The spelling of 221025660 in words is "two hundred twenty-one million, twenty-five thousand, six hundred sixty".